Process of treating wood for pencils.



UNITED STATES PATENT oF i "PROCESS F",TREATING woon son 'rnivoirs-T011511, whom it may concern:

Be- ;itknown j'that I, SAMUEL IInmiY CRooKEn, a subject of the KingofGleat- Britainandllreland,residing at 9 St; James Walk, in the countyof London, England, ha-veanvented a.,certa1n. new and useful Process ofTreating: 00d vfor Pencils, of

which. the following is a specification. This invention relates/to theclass of pencllsof that'class in Whichthe leads are surrounded bywoodenfholders which are cut away} fromrtime to time to. expose freshportions of the leads toreplace those which have been worn off by use,and the object of this invention is to provide wood for lead pencilsof-this particular class which may be easily cut or sharpened s Theprincipal features 1 of the invention consist in the chemicalpreparation or treatpencil leads by partial decomposition of the -woodby liquid either in a closedv vessel or ment of the wood for the woodenholders of contained by a vessel. open to the atmosphere, and depositingapore. filling material in the wood; and combining the wooden holdersmade from the wood so treated with I pencil leads, and the object of myinvention is to obtain by the treatment of compara- 'tively cheap andcommon wood the easy cutting quality and color required for a pencilwood which may be used as a substitute for the red cedar now almostuniversally used for lead pencils.

In carrying out my invention in one con venient manner a suitable wood,such as for example alder or bass wood, is cut up into pencil slats andplaced in a suitable vessel. A decomposing liquid. 4 consisting of watercontalning about one per cent. of commercial sulfuric acid is thenpoured into the vessel to cover the slats and heat is applied and theslats are boiled for about one half hour or until a reddish tint o-rcedar color 18 produced; when the liquid is withdrawn Without removingthe slats and the vessel is refilled with paraffin wax preferably in amolten state. Heat is again applied to raise thetemperature of the waxto a little over the boiling point of water and preferably to.

about 214 Fah. at which temperature it is maintained until sufficientwater has been removed from the slats by evaporation to I allow the woodto absorb a certain quantity of wax. The vessel containing the slats andthe liquid is provided with a liquid gage Specification of LettersPatent. .i Application filed lanuary26,1909. Seria1 Nd. 47

and the gradual descent of the wax levelin Patented July 11,1911.

the gage indicates the quantity of wax going into ;the slats. as c thewater evaporates. Thus the amount of wax enterlng the wood can beregulated and controlled which is an essential feature-of my inventionas complete saturation-of the wood with wax renders theslats unsuitablefor gluing and con sequently unsuitable for pencil making; hen; therequired quantity ofwax hasbeen absorbedby the slats the liquidwax iswithdrawn from the vessel. The slats are then dried in a temperaturehigher than the melt' reddish color when boiled in dilute sulfuric 1acid, There-are some woods which do not develop the required color whenso treated, as chestnut and some pine woods and I do not employ these,but I do not restrict myself to the woods before named nor to the use ofparaflin wax as I may use any equivalent pore filling material whichimproves the cutting qualities of thewood.

It is evident that modifications may be made within the scope of theinvention. F or example the slats may be treated in a closed vessel andthe treatment carried out.

under pressure.

' The slats from which ordinary pencils are mostly made and which itisintended to treat by this process average in size about? inches long by2:} inches wide by f ths of an inch thick as it will be. understood thatthese slats vary in length, width and thickness in. accordance with thesize of the pencil to be manufactured and they may be very much smallerand again very much larger. Different woods will absorb varying amountsof paraflin wax or other pore filling material before reachingsaturation and various pen- .cils may require different degrees ofhardness or softness in the texture of the wood according as a hard leador a soft lead may be embedded in the wood and to obtain this result agreater or less proportion of the pore filling material is absorbed bythe wood. I claim: l. A process for treating wood for holders of leadpencils consisting in immersing it in hot dilute sulfuric acid until areddish tint is produced and afterward impregnating the same with aregulated quantity of waxy material which shall improve the cut-- tingqualities of the wood, substantially as described.

.2. A process for treating wood for use in pencils, consisting inimmersing it in a solution of about one percent. sulfuric acid, boilinguntil a-reddish tint is produced and then impregnating the wood with aregulated quantity of waxy material which shall pencils, consisting inimmersing it in a solut1on of sulfuric acid, bOlllIlg until a reddishtint is produced, impregnatlng the wood with a regulated quantity ofwaxy material at a temperature sli htly above the boiling point ofwater, and withdrawing the remainder of the said material. V

5. A process for treating wood for use in pencils, consisting inimmersing it in a solution of sulfuric acid, boiling until. a reddishtint is produced, impregnating the wood with a regulated quantity ofwaxy material at a temperature slightly above the boiling point ofWater, withdrawing the remainder of the said material, and drying thewood at a temperature above the melting point of the said material.

6. A process for treating wood for use in pencils, consisting inimmersing it in hot dilute sulfuricacid until a reddish tint is producedand afterward impregnating the same with a regulated quantity of liquidparafiin, substantially as described.

In witness whereof I have hereunto set my hand in the presence of twowitnesses.

SAMUEL HY. CROCKER.

. Witnessesr JNo. H. RYAN,

FRANK W. PATTISQN.

